Mother–child bed-sharing associated with more wheezing in early childhood

Abstract

Household crowding, including the number of people sharing the child’s bedroom, may place young children at risk of acute lower respiratory infection [1]. However, crowding may also protect against asthma, according to the hygiene hypothesis [2]. Thus bed-sharing in early childhood might either increase or decrease the risk for asthma. On the other hand, parents may adopt bed-sharing practices that allow for closer monitoring of their already asthmatic children. In a recent review, Koinis-Mitchell et al. [3] suggested that asthma underlies sleep problems as a consequence of sleep disordered breathing and frequent awakenings at night. No studies have yet investigated the associations between bed-sharing and asthmatic symptoms. In the current study, we assessed whether bed-sharing practices protect young children from developing asthmatic symptoms, or place them at risk for these symptoms. In the current population-based prospective cohort study ( N = 5,543) we assessed bed-sharing at ages 2 and 24 months, and wheezing, the most important asthma symptom, at ages 1 through 4 years by questionnaires. Generalized estimating equation models (GEE) were used to assess repeated measures of wheezing, and multinomial regression analysis to assess patterns of wheezing over time. Results indicated that bed-sharing at 2 or 24 months were not associated with wheezing at later ages. However, assessing patterns of wheezing over the preschool years shows that bed-sharing at 24 months is associated with early-only wheezing (i.e. wheezing reported only at ages 1 and 2 years; OR 1.64, CI 1.13–2.37, p < .01), even after controlling for maternal educational level, history of atopy and asthma, smoking, body mass index (BMI), breastfeeding, parity, child ethnicity, gender, gestational age at birth, daycare attendance, pet keeping, eczema, and lower respiratory tract infections. Bed-sharing at 2 and 24 months of age was not associated with wheezing later in the preschool years, or with persistent wheezing over time. However, children who bed-shared with their parents at 24 months of age had higher odds to be in the early-only wheezing group. This suggests that bed-sharing children wheeze more, but only at early ages. The transient nature of these children’s wheezing might be associated with the relatively high prevalence of viral infections in the first years of life. It could also be that parents of early-only wheezers bring their child to the parental bed in order to monitor their breathing. This large longitudinal study is the first to explore the associations between bed- sharing practices and wheezing, and shows important associations between this sleep related parenting practice and children’s asthma symptoms. The Generation R Study is conducted by the Erasmus Medical Centre in close collaboration with the School of Law and the Faculty of Social Sciences at the Erasmus University, Rotterdam, the Municipal Health Service, Rotterdam area, and the Stichting Trombosedienst and Artsenlaboratorium Rijnmond (Star-MDC), Rotterdam. We gratefully acknowledge the contribution of general practitioners, hospitals, midwives and pharamacies in Rotterdam.